Fruit Tree Pests

I have been told that one of the hardest areas in farming organically is fruit trees. Pests love fruit trees, and especially the developing and mature fruit. Insects and animals can pose serious challenges. Let's explore these, and suggested treatments.

Insects

A relative has in the past had extensive damage from several insects in his orchard. He has developed some creative solutions. He uses an electric zapper with two types of light source (florescent and incandescent.) Below the zapper he places a small wading pool of water, and wets the water with a detergent. In his experience, many moths and insects will be attracted and stunned, but not be killed. When stunned, the insect will fall to the ground, and with the wading pool below the moth kill is dramatically increased. Helpful insects are not strongly attracted to the zapper, while moths are strongly attracted. Moth pupae are damaging to many crops on the homestead. One person told me they could not think of a beneficial moth-- all are destructive to something. They love to fly at night, and if you have electricity, you can zap / drown a lot of them.

Another promising control measure is a clay product called Surround. It coats the tree and fruit in such a way as to confuse insects and camouflage the fruit which limits infestations. This product can be washed off with rain, and has to be applied weekly.

Peach Tree Borer

Traps can indicate the presence of adult moths, and once present, you will soon have eggs on the lower part of your peach trees. The eggs hatch in 7 days, and the larvae descend to ground level and burrow into the bark. Control measures applied to the tree need to be precisely timed to catch the eggs or larva before penetration below the bark.

Some farmers are convinced that the bug zapper has eliminated the peach tree borer damage. This moth is active in the day, but I have read reports that they mate at night, and therefore would be susceptible to the bug zapper.

• CO State University Fact Sheet (web)
• Peach Tree Borer trap and lure (web order)

Plum Curculio

This small snout beetle, 1/4 inch long, dark brown in color with patches of white or gray, lays its eggs on developing fruit, and the larva will burrow in and often destroy the fruit. Home gardeners can help reduce future problems from the Curculio by picking up the damaged apples as they fall off the tree and destroying them before the adults emerge. In apples, the larvae will only complete development in fruit drops.

• Fact Sheet (web)
• Fact Sheet (web)

Animals

Birds can quickly ruin a crop of mature fruit. I have a friend who watched a bird go from peach to peach throughout an entire tree taking one gouging bite from each nearly mature peach. The bird was doing great damage, and not eating hardly any of the fruit to become satiated. In a short time, such damage will rot and spoil the entire peach. Netting the entire tree is suggested if you have this type of damage. It is almost impossible to keep the birds out otherwise. Select a netting size that will not entangle the birds that land on the netting.

Strings draped through the tree foliage has been reported to discourage crows from staying in the tree.

I have seen electric wire around the trunks of fruit trees to discourage squirrels and similar from climbing the trunk to destroy fruit.

Deer and raccoon can be best excluded with electric fencing.


Resources

• Overview of insect pests and control measures (web)
• Companion planting to deter pests (web)
• Seasonal Checklist for the Holistic Orchard (web)
• Kaolin Surround use as a blossom time treatment (web)
• Pure Neem Oil (web order)
• Organic grower supplies (web order)